In response to the growing number of HIV infected adolescents and young adults in this country and abroad, the Adolescent Trials Network (ATN) will continue to create opportunities to conduct an array of studies to better understand this infection. The ATN will specifically seek to better understand how infection with this virus can be prevented, how infection is initiated, how the infection evolves in those infected, how progression of illness can be slowed, and how seriously ill persons can be successfully treated. Efforts to prevent infection will be carried out through the community-based Connect to Protect (C2P) project and will focus on continued efforts to develop the primary prevention infrastructure necessary for vaccine research, microbicide research, pre-exposure prophylaxis (PrEP), and theoretically based behavioral interventions to reduce risk behaviors. Secondary prevention will focus on preserving the health of HIV infected youth. Crucial to these efforts will be studies that will identify infected youth early and successfully link them to care. Similarly important will be studies of the pharmacogenomics of antiretroviral agents by themselves and in combination with other drugs and studies aimed at increasing adherence, promoting positive behaviors, and limiting risks in all infected adolescents. Tertiary prevention efforts will focus on the development of therapeutic options for adolescents further along in their disease process, as well as to identifying psychological and ancillary services that might help improve health. The ATN will similarly promote studies that look at the life-decision making process, coping mechanisms to deal with life-threatening illness, and end-of-life planning. RELEVANCE: This study seeks to find ways to understand, prevent, and treat HIV infection in adolescents and young adults. It will study how communities can make changes to prevent the infection as well as studying how individuals infected with the virus can be kept healthy. Finally, it will try to find ways to restore the health of youth who have become very ill as a result of this infection.